In this study, the application of infrared thermal imaging technology in the detection of fresh agricultural products in cold chain of food was explored. Two fresh agricultural sugar beets and cucumbers were selected and placed on a tray, each covered with three materials (Tyvek, Metallized PET, Metallized Foam PET) to produce a different coated food tray. The food tray was placed in the cold room during the simulation distribution. The surface temperature of the food tray was detected and compared with the infrared thermal imaging camera and the needle detector. The results showed that the temperature measured by the infrared thermal imaging camera and the detecting thermometer was 1.9~6.0 ℃. High emittance of the metal PET results in significant temperature reading errors on the food tray when measured with an infrared thermal imaging camera. Tyvek's emission rate was similar to that of the infrared thermal imaging camera, which obtained a lower temperature error. This study could provide theoretical explanation and data support for the application of infrared thermal imaging technology to temperature monitoring of food pallet.